FRANCES Z. BROWN if a former director on the staff of both the Obama and Trump National Security Councils. She is a Fellow at the Carnegie Endowment for International Peace and a doctoral candidate at Oxford. MARA KARLIN is Associate Professor at Johns Hopkins University's School of Advanced International Studies. She spent nearly a decade as a Defense Department policymaker and is the author of Building Militaries in Fragile States: Challenges for the United States[1].

What does an “America first[2]” national security strategy look like in action? The White House provided a hint in April, when news broke[3] that National Security Adviser John Bolton had asked Arab nations, including Egypt and possibly Saudi Arabia, to supply ground forces to replace U.S. troops in Syria[4]. (This came only weeks after U.S. President Donald Trump announced[5] his desire to “bring our troops back home.”) Although details are scarce, Bolton’s new initiative appears to mirror a broader talking point coming from the Trump administration: rather than putting American lives at risk, the United States will work “by, with, and through” local forces to achieve its national security objectives.

Champions of the by-with-through model argue that it is a better (and cheaper) means of fighting wars and winning the peace than sending U.S. troops into harm’s way. Testifying before Congress in March, General Joseph Votel of U.S. Central Command explained[6] that “working ‘by, with, and through’ our allies and partners allows us to multiply the effect of relatively modest commitments,” ensuring that the Middle East “never again requires a mass deployment of U.S. forces.” For Trump, this sounds like the ultimate deal: working with local partners will enable the United States to get more of its desired security outcomes for less of its blood and treasure.

Working with local partners is not a new model: the administrations of George W. Bush and Barack Obama both relied heavily on local partners to fight the “war on terror,” whether through major efforts to develop national armies and police forces in Iraq and Afghanistan or through more limited partnerships across Africa, Asia, and the Middle East. Today, however, it has assumed a new centrality as Trump seeks to wind down U.S. military commitments abroad. Votel has said[6] that the by-with-through model now underpins U.S. campaigns in Afghanistan, Egypt, Iraq, Lebanon, Syria, and Yemen. Defense Secretary James Mattis cited[7] it on a recent visit to